Initial game loop implemented with fixed time step. Loads tiles and levels directly from uncompressed DAVE.EXE. Draws levels 20x10 tiles at a time with support for scrolling. Renderer is set to logical size of 320x200 with SDL automatically handling scaling and letterboxing. Makefiles work with MinGW now.

Makefile

@@ -33,7 +33,9 @@ CFLAGS_g +=
 
 # libs
 ifdef ISWIN
-	LDFLAGS_g += 
+	CFLAGS_g += -I../SDL2-2.0.8/include
+	LDFLAGS_g += -L../SDL2-2.0.8/lib \
+		-lmingw32 -lSDL2main -lSDL2 -lopengl32 -mconsole
 else
 	CFLAGS_g += -I/usr/include/SDL2
 	LDFLAGS_g += -lSDL2

lmdave.c

@@ -7,55 +7,161 @@ game_assets_t* g_assets = NULL;
 
 // initialize a new game state
 void init_game() {
-	gs->quit = 1;
-	gs->current_level = 1;
+	gs->quit = 0;
+	gs->current_level = 0;
+	gs->view_x = 0;
+	gs->view_y = 0;
+	gs->scroll_x = 0;
+
+	// returns array of NUM_EXE_LEVELS that was loaded by the util lib
 	gs->levels = GetLevels();
 }
 
 // initialize game assets
 void init_assets( SDL_Renderer* r ) {
+	// get loaded tile surface array from util lib
+	SDL_Surface** tileSfcs = GetTileSurfaces();
+
+	// convert each surface from util's array to g_asset texture array
+	for ( int i = 0; i < NUM_EXE_TILES; ++i ) {
+		g_assets->tile_tx[i] = SDL_CreateTextureFromSurface( r, tileSfcs[i] );
+	}
 }
 
 // poll input
 void check_input() {
+	SDL_Event ev;
+	SDL_PollEvent( &ev );
+
+	if ( ev.type == SDL_QUIT ) gs->quit = 1;
+
+	if ( ev.type == SDL_KEYDOWN ) {
+		switch ( ev.key.keysym.sym ) {
+		case SDLK_RIGHT:
+			gs->scroll_x = 15; break;
+		case SDLK_LEFT:
+			gs->scroll_x = -15; break;
+		case SDLK_DOWN:
+			gs->current_level++; break;
+		case SDLK_UP:
+			gs->current_level--; break;
+		}
+	}
 }
 
 // update game logic
 void update_game() {
+	if ( gs->current_level == 0xff ) gs->current_level = 0;
+	if ( gs->current_level > NUM_EXE_LEVELS - 1 )
+		gs->current_level = NUM_EXE_LEVELS - 1;
+
+	// scrolling
+	if ( gs->scroll_x > 0 ) {
+		if ( gs->view_x == 80 ) gs->scroll_x = 0;
+		else { gs->view_x++; gs->scroll_x--; }
+	}
+	if ( gs->scroll_x < 0 ) {
+		if ( gs->view_x == 0 ) gs->scroll_x = 0;
+		else { gs->view_x--; gs->scroll_x++; }
+	}
 }
 
 // draw to renderer
 void render( SDL_Renderer* r ) {
+	// clear backbuffer
+	SDL_RenderClear( r );
+
+	SDL_Rect dst;
+	// draw level 20x10 tiles at 16x16px
+	for ( int j = 0; j < 10; ++j ) {
+		dst.y = j * 16;
+		dst.w = 16; dst.h = 16;
+		for ( int i = 0; i < 20; ++i ) {
+			dst.x = i * 16;
+			uint8_t til = gs->levels[gs->current_level].tiles[j * 100 + gs->view_x + i];
+			SDL_RenderCopy( r, g_assets->tile_tx[til], NULL, &dst );
+		}
+	}
+
+	// flip buffers
+	SDL_RenderPresent( r );
 }
 
 // rendering scale
-const uint8_t R_SCALE = 3;
+//const uint8_t R_SCALE = 3;
 
 int main( int argc, char** argv ) {
-	// initialize resources from DAVE.EXE
+	// load resources from DAVE.EXE
 	LoadTiles();
 	LoadLevels();
 
 	gs = malloc( sizeof(game_state_t) );
 	init_game();
 
-	SDL_Window* window = NULL;
-	SDL_Renderer* renderer = NULL;
-	SDL_CreateWindowAndRenderer( 320 * R_SCALE, 200 * R_SCALE, 0, &window, &renderer );
+	if ( SDL_Init( SDL_INIT_VIDEO ) )
+		SDL_Log( "SDL Init error: %s\n", SDL_GetError() );
+
+	// SDL_Window* window = NULL;
+	// SDL_Renderer* renderer = NULL;
+	// if ( SDL_CreateWindowAndRenderer( 960, 720, SDL_WINDOW_RESIZABLE, &window, &renderer ) )
+	// 	SDL_Log( "SDL WindowAndRenderer error: %s\n", SDL_GetError() );
+
+	// create window and renderer
+	SDL_Window* window = SDL_CreateWindow( "lmdave", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+		1280, 720, SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_OPENGL );
+	if ( window == NULL ) {
+		SDL_Log( "SDL_CreateWindow error: %s\n", SDL_GetError() );
+		SDL_Quit(); return EXIT_FAILURE;
+	}
+
+	SDL_Renderer* renderer = SDL_CreateRenderer( window, -1, SDL_RENDERER_ACCELERATED
+		| SDL_RENDERER_PRESENTVSYNC );
+	if ( renderer == NULL ) {
+		SDL_DestroyWindow( window );
+		SDL_Log( "SDL_CreateRenderer error: %s\n", SDL_GetError() );
+		SDL_Quit(); return EXIT_FAILURE;
+	}
+
+	// set internal rendering size
+	SDL_RenderSetLogicalSize( renderer, 320, 200 );
+	//SDL_RenderSetScale( renderer, R_SCALE, R_SCALE );
+	// scaling hint
+	//SDL_SetHint( SDL_HINT_RENDER_SCALE_QUALITY, "linear" );
 
 	g_assets = malloc( sizeof(game_assets_t) );
 	init_assets( renderer );
 	// tile surfaces should be converted as textures inside g_assets now
 	FreeTileSurfaces();
 
+	// clear initial frame
+	SDL_SetRenderDrawColor( renderer, 0, 0, 0, 0xff );
+	SDL_RenderClear( renderer );
+
 	// main loop
 	while ( !gs->quit ) {
+		// fixed timestep
+		uint32_t st = SDL_GetTicks();
+
 		check_input();
 		update_game();
 		render( renderer );
+
+		//uint32_t et = SDL_GetTicks();
+		uint32_t delay = 16 - (SDL_GetTicks() - st);
+		delay = delay > 16 ? 0 : delay;
+		SDL_Delay( delay );
 	}
 
+	// destroy each tile texture
+	for ( int i = 0; i < NUM_EXE_TILES; ++i )
+		SDL_DestroyTexture( g_assets->tile_tx[i] );
 	free( g_assets );
 	free( gs );
-}
 
+	// cleanup SDL
+	SDL_DestroyRenderer( renderer );
+	SDL_DestroyWindow( window );
+	SDL_Quit();
+
+	return EXIT_SUCCESS;
+}

lmdave.h

@@ -10,9 +10,11 @@
 typedef struct {
 	uint8_t quit;
 	uint8_t current_level;
+	// view and scroll are per tile
 	uint8_t view_x, view_y;
+	int8_t scroll_x;
 
-	level_t* levels; // grabbed from util
+	level_t* levels; // grabbed from util, NUM_EXE_LEVELS count
 } game_state_t;
 
 // game assets
@@ -22,4 +24,3 @@ typedef struct {
 } game_assets_t;
 
 #endif
-

util/Makefile

@@ -32,7 +32,9 @@ CFLAGS_g += -DUTIL_BIN
 
 # libs
 ifdef ISWIN
-	LDFLAGS_g += 
+	LDFLAGS_g += -L../../SDL2-2.0.8/lib \
+		-lmingw32 -lSDL2main -lSDL2 -mconsole
+	CFLAGS_g += -I../../SDL2-2.0.8/include
 else
 	CFLAGS_g += -I/usr/include/SDL2
 	LDFLAGS_g += -lSDL2

util/tiles.c

@@ -1,6 +1,7 @@
 // extract tilesxxx.bmp from uncompressed DAVE.EXE
 #include <stdint.h>
 #include <inttypes.h>
+#include <stdio.h>
 
 #include "util.h"
 

util/util.h

@@ -20,7 +20,7 @@ void FreeTileSurfaces();
 // byte[24] unsed padding
 // note: player start and monster starts are hardcoded
 typedef struct {
-	int8_t path[256];
+	uint8_t path[256];
 	uint8_t tiles[1000];
 	uint8_t pad[24];
 } level_t;
@@ -32,4 +32,3 @@ void SaveLevels();
 void CreateWorldMap();
 
 #endif
-